El Ninos are far costlier than once thought, in the trillions, study says—and one's brewing now

The natural burst of El Nino warming that changes weather worldwide is far costlier with longer-lasting expenses than experts had thought

The natural burst of El Nino warming that changes weather worldwide is far costlier with longer-lasting expenses than experts had thought, averaging trillions of dollars in damage, a new study found.

An El Nino is brewing now and it might be a big — and therefore costly — one, scientists said. El Nino is a temporary and natural warming of parts of the equatorial Pacific, that causes droughts, floods and heat waves in different parts of the world. It also adds an extra boost to human-caused warming.

The study in Thursday's journal Science totals global damage with an emphasis on lasting economic scars. It runs counter to previous research that found, at least in the United States, that El Ninos overall aren't too costly and can even be beneficial. And some — but not all — outside economists have issues with the new research out of Dartmouth College, saying its damage estimates are too big.

Study authors said the average El Nino costs the global economy about $3.4 trillion. The strong 1997-1998 one cost $5.7 trillion. The World Bank estimated the 1997-1998 El Nino cost governments $45 billion, which is more than 100 times smaller than the Dartmouth estimate.

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But the Dartmouth team said they are looking at more than the traditional costs and for longer time periods.

“We have this sense that El Nino is a really big hammer that hits the Earth system every few years. But we didn’t have as much of a handle on its sort of macroeconomic implications, both what that means just on a year-to-year basis and what that might mean with future global warming,” said study lead author Christopher Callahan, a climate impacts researcher at Dartmouth.